Synthesis of novel furan and thiophene PAH'S related to acephenanthrylene

The total syntheses of furan and thiophene PAH's related to acephenanthrylene are reported. Cyclobutanones which were obtained by 2 + 2] addition of ketenes with 2,3-dihydrofuran or 2,3-dihydrothiophene regioselectively could be converted into angular PAH skeleton molecules by rearrangements with polyphosphoric acid. 2,3-Dichloro-5,6-dicyanobenzoquinone was applied for aromatization to achieve the formation of PAH's.